INSECTS INJURIOUS TO SMALL GRAINS 147 



When full grown the larvae enter the ground and usually 

 form cocoons, in which they pass the winter in the pupal stage* 

 though they often hibernate without such protection. Though 

 doubtless there is usually but one brood in a season, observations 

 by Professor F. M. Webster and others seem to point to the fact 

 that there sometimes are two broods, as adults have been observed 

 from August into November. 



Besides wheat, the wheat-midge also sometimes injures 

 rye, barley, and oats. 



Remedies. Plowing infested fields in the fall so deeply that 

 the midges will be unable to reach the surface upon developing 

 in the spring is by far the best means of controlling this pest, 

 while burning the stubble previous to plowing, and a rotation 

 of the crop, will also be of considerable aid. 



The English Grain-louse * 



The most common plant-louse affecting wheat and other small 

 grains is a large green species which is always to be found on 

 wheat plants, but which occasionally increases very rapidly, and 

 clustering on the ripening heads sucks the juices so as to seriously 

 injure the quality and weight of the wheat. 



In the North the first individuals are found on young wheat 

 in April, though during open winters they may be found on the 

 plants, and in the South they continue to reproduce during most 

 of the winter in open seasons. The aphides feed upon the leaves 

 until the grain commences to head, when they assemble on the 

 heads among the ripening kernels. The females give birth to 

 live young, bearing from 40 to 50 each, which become full grown 

 in ten days to two weeks, and then reproduce, as is the usual 

 method of reproduction with plant-lice (see page 442), so that they 



* Macrosiphum granaria Buckton. Family Aphidida. A nearly related 

 species, Macrosiphum cerealis Kaltenbach, has very similar habits, is commonly 

 associated with the species, and has not been distinguished from it by most 

 writers. It may be recognized by lacking the blackish markings on the 

 abdominal segments. See Pergande, Bulletin 44, Bureau of Entomology, 

 U. S. Dept. Agr. 



